This invention relates to a phone apparatus having a redialing function of redialing a dialing number again.
Heretofore, a phone apparatus or set with a redialing function has been widely sold and used. In such a phone apparatus, a dial number of a called party is stored or stored in a memory (redialing memory) and is redialed to the same called party once after the dialing number is dialed to the called party or person.
In such a phone apparatus with the redialing function, it is necessary to prevent an unauthorized person from intercepting or stealing stored contents stored in a memory provided in the phone apparatus. Otherwise, a bank account number and/or a password might be informed and stolen by the unauthorized person by the use of the redialing operation. To this end, a telephone line or path is captured again after a speech or conversation is finished through the phone apparatus. Thereafter, a meaningless dial number is dialed to be rewritten on a previous dial number and to erase the previous dial number. Alternatively, stored contents dialed previously are saved into a cache or a peculiar memory by a preselected operation and can be read out of the cache memory only when a password or a key number is given to the memory.
For example, an existing phone apparatus having the redialing function comprises a hooking switch, a calling circuit, a handset, a ring generator, a designating signal transmitting circuit, a controller, a number display, a memory, a redialing button, and a dialing button.
The phone apparatus is connected to a telephone line. The hooking switch switches internal blocks provided in the phone apparatus. The controller controls operations of the phone apparatus. The number display displays stored contents such as a dialing number stored in the memory. The memory stores therein informations worked by the controller.
In the phone apparatus having the redialing function, a first dialing number is transmitted as a designating signal to the telephone line, is displayed on the number display, and is stored in the memory, by pushing the dialing button after off-hooking. Next time, a second dialing number is transmitted as a designating signal to the telephone line, is displayed on the number display, and is stored in the memory by newly pushing the dialing button 11 as like to the first dialing number. When a calling is finished by on-hooking the handset onto the hooking switch of the phone apparatus, the dialing number stored in the memory is stored as a redialing number in the memory. Hence, when the redialing button is pushed after off-hooking, the redialing number stored in the memory is read out by the controller, is transmitted as the designating signal to the telephone line, and is displayed on the number display.
In the existing phone apparatus having the redialing function, there is however a disadvantageous matter that regrettably the dialing number dialed can be easily intercepted by the redialing operation by an unauthorized person. For example, when the user uses a telephone bank cashing service with using the telephone apparatus, bank account and key numbers input through the phone apparatus are stored as the dialing number in the redialing memory. The unauthorized person can regrettably intercept, by only pushing the redialing button, the bank account and the key numbers.
Furthermore, as the prevention of the interception, the phone apparatus is operated as mentioned above. Namely, the user of the phone apparatus, after the use of the telephone bank cashing service, off-hooks again and dials a meaningless or an optional dial number so that the dialing number is rewritten on the bank account and the key numbers last stored in the redialing memory and that the bank account and the key numbers are deleted. Furthermore, the user operates the evacuating operation so that the bank account and the key numbers last stored in the redialing memory are evacuated to the evacuating memory previously provided in the phone apparatus. However, these operations are very troublesome, the user may forget how to surely operate an evacuating function, and therefore the unauthorized person can regrettably intercept the bank account and the key numbers. Therefore, the existing phone apparatus having the redialing function cannot surely prevent the unauthorized person from intercepting stored contents stored in the memory.
Another existing telephone apparatus having the redialing function capable of deleting the stored contents, telephone apparatuses are for example disclosed in Japanese Patent Unexamined Publications (A) Nos. 78356/1991 and 321868/1996.